net/mlx5: Reorder few command cases to reflect their natural order

Move the commands related to scheduling elements and vport qos to
a suitable location (according to the MLX5_CMD_OP enum values) in
the command string and internal error helpers.

This patch doesn't change any functionality.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>